The present invention relates to a magnetic disk drive and a magnetic head slider.
A conventional magnetic disk drive reads or writes information while a magnetic head slider which carries a magnetic read/write head thereon flies over a rotating magnetic recording medium. When the flying magnetic head slider undergoes disturbance from the exterior of the magnetic disk drive or comes into contact with the rotating magnetic recording medium, it vibrates in its flying height direction.
To attain higher density magnetic recording, the flying height of the magnetic head slider has been becoming increasingly low every year and at present the flying height is as low as near 10 nm. However, the lowering of the flying height of the magnetic head slider increases the probability of contact between the magnetic head slider and the surface of the magnetic recording medium, with the result that the reliability of the magnetic disk drive may be deteriorated. Therefore, it is necessary for the magnetic head slider to fly stably in the interior of the magnetic disk drive.
To stabilize the flying of the magnetic head slider in the conventional magnetic disk drive, the following techniques have been adopted. For example, like a negative-pressure magnetic head slider, a negative-pressure groove is formed in an air bearing surface of the magnetic head slider to enhance the rigidity of an air bearing between the magnetic head slider and the magnetic recording medium, thereby enhancing the resistance to disturbance. A fine texture shape is formed in the air bearing surface of the magnetic head slider to diminish a frictional force induced upon contact of the magnetic head slider with the magnetic recording medium.
An attempt has recently been made to improve the rail surface shape of the air bearing surface of the magnetic head slider, thereby stabilizing the flying of the magnetic head slider. For example, in Japanese Patent Laid-open No. 2000-353370 (Patent Literature 1), a pressure control groove is formed in a negative-pressure groove of the air bearing surface of a magnetic head slider to control the flying height, thereby suppressing variations in flying height of the magnetic head slider to stabilize the flying of the same slider. Further, for example, in Japanese Patent Laid-open No. 2004-71140 (Patent Literature 2), an air bearing surface of a magnetic head slider is formed in a U-shape which opens toward a leading edge side to decrease the sensitivity of a change in flying height of the air bearing surface caused by variations in manufacture, for example, thereby stabilizing the flying of the magnetic head slider. These techniques can be easily implemented by merely increasing the number of steps in the machining process for the air bearing surface of the conventional magnetic head slider. Taking this point into account, it can be said that the above techniques are effective in stabilizing the flying of the magnetic head slider.
However, the magnetic disk drives disclosed in Patent Literatures 1 and 2 are for improving the stability during flying of the magnetic head slider to prevent the occurrence of a large vibration of the magnetic head slider. When the magnetic head slider vibrates largely in its flying height direction due to a shock from the exterior of the magnetic disk drive or due to an environmental change or when the magnetic head slider vibrates due to contact thereof with the magnetic recording medium, the magnetic disk drives disclosed in Patent Literatures 1 and 2 are not so effective. The magnetic head slider and the magnetic recording medium are designed so as to permit a slight mutual contact. However, when they are in continuous or strong contact with each other, it is very likely that one or both may suffer physical and magnetic damage. If a large vibration of the magnetic head slider continues, it is very likely that continuous or strong contact of the magnetic head slider with the magnetic recording medium may occur and therefore it is desired to damp the vibration of the magnetic head slider quickly.